Hi, I've got 6 month old boy/girl twins and my DS is really active, he rolls both ways, turns on his tummy and is showing willingness to start crawling. My DD on the other hand will easily roll from her back to her tummy but then seems to get stuck and just sticks her arms out and gets distressed. I've tried teaching her to tuck her arm under and get back on her back but she doesn't seem to have picked it up. Should I be worried? It's just so easy to compare the two of them and their development. On the other hand she's much more chatty than DD and has a wider range of sounds so maybe they're just learning skills differently. Thanks for any advice!